A study of genetic algorithms for solving the school timetabling problem.

Abstract

The school timetabling problem is a common optimization problem faced by many primary and secondary schools. Each school has its own set of requirements and constraints that are dependent on various factors such as the number of resources available and rules specified by the department of education for that country. There are two objectives in this study. In previous studies, genetic algorithms have only been used to solve a single type of school timetabling problem. The first objective of this study is to test the effectiveness of a genetic algorithm approach in solving more than one type of school timetabling problem. The second objective is to evaluate a genetic algorithm that uses an indirect representation (IGA) when solving the school timetabling problem. This IGA approach is then compared to the performance of a genetic algorithm that uses a direct representation (DGA). This approach has been covered in other domains such as job shop scheduling but has not been covered for the school timetabling problem. Both the DGA and IGA were tested on five school timetabling problems. Both the algorithms were initially developed based on findings in the literature. They were then improved iteratively based on their performance when tested on the problems. The processes of the genetic algorithms that were improved were the method of initial population creation, the selection methods and the genetic operators used. Both the DGA and the IGA were found to produce timetables that were competitive and in some cases superior to that of other methods such as simulated annealing and tabu search. It was found that different processes (i.e. the method of initial population creation, selection methods and genetic operators) were needed for each problem in order to produce the best results. When comparing the performance of the two approaches, the IGA outperformed the DGA for all of the tested school timetabling problems.